Thermal-operated valve



y 1969 A. J. CORNELIUS 3,456,722

THERMAL-OPERATED VALVE Filed Dec. 29, 1966 FIG. E

i FIG. 2

INVENTOR.

A. J. CORNELIUS F/G. a %Wy z A 7' TORNEVS United States Patent 3,456,722 THERMAL-OPERATED VALVE Archie J. Cornelius, Bartlesville, 0kla., assignor to Phillips Petroleum Company, a corporation of Delaware Filed Dec. 29, 1966, Ser. No. 605,821 Int. Cl. E21b 43/16; F16k 17/38 U.S. Cl. 166-64 8 Claims ABSTRACT OF THE DISCLOSURE The invention relates to a heat-operated valve assembly and to a method of temperature control of an area subject to overheating, using the assembly.

The invention has been developed particularly for use in in situ combustion projects in oil sands wherein certain wells must be protected from excessive temperatures. Heretofore, this has been accomplished by installing a thermocouple in the well and utilizing the signal therefrom to regulate the flow of cooling fluid (usually water) into the well. The thermocouple cables are quite expen sive and somewhat undependable in the downhole environment. A minimal amount of electrical instrumentation is always required to automate the system which adds to the expense, complexity, and unreliability of the method being used. Usually, a separate tubing has been used to inject the cooling water and unless special care is taken to insure that this tubing is maintained full of water, a delay occurs as the tubing is filled which sometimes results in burning out the thermocouple cables and/or damaging the well equipment.

Accordingly, it is an object of the invention to provide an inexpensive, effective, and reliable means for delivering fluid coolant to an area subject to overheating, when a set or selected temperature limit is exceeded. A further object is to provide a sure and effective process or method for controlling the temperature of an area subject to overheating. Another object is to provide a device and method for controlling downhole temperature in an in situ combustion well. Other objects of the invention will become apparent to one skilled in the art upon consideration of the accompanying disclosure.

A broad aspect of the invention comprises a heat-operated valve comprising a check valve in conjunction with an actuating rod which expands upon heating to open the check valve. The valve is positioned in a fluid coolant line terminating in the area in which heat control is desired with the check valve opening upstream in the valve body and the elongator extending from a fixed point downstream to the proximity of the check valve head so that upon expansion of the actuator rod the valve head is pushed ofi its seat to allow flow of coolant into the hot area to be cooled.

Thus, according to the invention, there is provided a heat-operated valve assembly comprising, in combination: an elongated hollow valve body having an axial inlet port in one end, a transverse valve seat in said inlet port, at least one outlet port thru its wall downstream of said seat, and means at said inlet port for attaching said valve body to a cooling fluid supply tube; a valve head disposed across said valve seat in said valve body, normally seated on said seat, and movable off said seat to- Patented July 22, 1969 ice ward said inlet end to permit fluid flow thru said valve body to said outlet port; a housing attached to the other end of said valve body coaxially therewith; and an elongated axially disposed heat expansible actuator rod, of substantially higher coeflicient of expansion than said housing, fixed within said housing to a section thereof remote from said valve head, and expansible at elevated temperatures into actuating contact with said valve head.

The valve assembly is particularly suitable for use in in situ combustion wells but it is also adaptable to any situation in which overheating of an area is likely to occur and prevention thereof is desired. Basically, it makes use of a differential coeflicient of thermal expansion to unseat a check valve when the set temperature limit is reached or exceeded using an actuating rod of higher coefficient of expansion than that of the supporting structure.

A more complete understanding of the invention may be had by reference to the accompanying schematic drawing of which FIGURE 1 is an elevational view thru a well equipped with the apparatus of the invention; FIG- URE 2 is a detailed longitudinal sectional view of one embodiment of the valve of the invention; and FIGURE 3 is a. similar view to FIGURE 2 showing another embodiment of the invention.

Referring to FIGURE 1, an oil stratum 10 is penetrated by a production well 12 in use in an in situ combustion operation. Well 12 is equipped with a perforated casing 14 extending thru stratum 10 and with a water line 16 leading from a water supply tank 18 to a heatoperated check valve 20 positioned downhole. A production line 22, above ground, connects with the well annulus for withdrawal of a production efliuent containing oil. It is also feasible to run a separate production tubing string in the well instead of producing thru the annulus and line 22.

Referring to FIGURE 2, valve body 24 is threaded onto water line 16 at the upper end and at the other end to a housing or skirt 26. Valve seat 28 is threaded into valve body 24 across the axial opening thru the valve body. Valve head 30 seats on valve seat 28 and is connected to a valve stem 32 by means of a screw 34 or other means. Stem 32 is provided with a flange 36 spaced a substantial distance from valve head 30 and this flange seats on shoulder 38 in the valve body. The check valve is biased in the closed position by a compressed spiral spring 40.

One or more outlet ports 42 for fluid coolant are provided thru the wall of valve body 24. In order to prevent flow of coolant thru the valve body below ports 42a threaded insert 44 is screwed into the valve body against packing 46. Valve stem or push rod 32 extends a substantial distance below insert 44 and the lower end thereof is surrounded by or telescopes with elongator or actuator rod 48 which is enclosed within skirt or housing 26 to which it is secured at its lower end by threaded disc 50 seated against lock nut 52. Rod 48 is welded, or otherwise fixed, to disc 50 as shown and is adjustable longitudinally within housing 26 to provide the desired temperature level for operation of the valve. A cap 54 is threaded into the lower end of housing 26 to prevent ingress of water, oil, etc. Actuator rod 48 is of substantially smaller diameter than the internal diameter of housing 26 to facilitate the elongation of the rod without undue friction with the housing. Drilled hole 56 in the upper end of rod 48 is of larger diameter than the diameter of valve stem or push rod 32 for the same purpose.

Referring to FIGURE 3, a tubular housing or valve body 60 encloses a ball check valve 62 of conventional construction and the ball is actuated (removed from its seat) by an elongator or actuator rod 64 which is threaded into a spider arrangement 66 and locked thereto by a 3 nut 68. A packer arrangement 70 just below outlet port 72 prevents flow of coolant into the lower end of the device so as to force the coolant thru ports 72.

The operation of the device described and shown in the drawing requires the use of a material in actuator rod 48 or 64 which has a substantially higher coefficient of expansion than the tubing or skirt from which the actuator'rod is supported at its lower end. The amount of clearance provided between the elongator or actuator rod and the point of contact with the valve for any given combination of materials in the actuator rod and the supporting housing determines the temperature at which the valve is opened by pushing the valve head off its seat. In other words, the spacing between the rod and its contact point with the valve is adjusted so that the rod will just contact the check valve at the selected maximum temperature limit to be tolerated in the particular application. A further temperature rise causes the metal rod to expand more than the case or housing, thereby unseating the check valve. The packing and side ports are provided so that the injected coolant does not cool the metal rod too quickly, which would cause the flow to fluctuate unduly. When the metal rod and sub-assembly cool below the set temperature, the check valve closes and shuts off the flow of coolant. The valve will continue to operate indefinitely without maintenance but can be made so that it can be retrieved from the well with a wire line when the set temperature limit is to be changed.

The housing for the actuator rod is preferably made of ordinary carbon steel and the actuator rod itself is preferably made of stainless steel which has a substantially higher coefficient of expansion. While stainless steel is the preferred material for the actuator rod, it may also be made of aluminum. Other materials for use in fabricating the actuator rod and its housing may be utilized, it being essential that the rod have a substantially higher coeflicient of expansion than the supporting housing.

In one embodiment of the invention, valve body 24 was constructed to attach to a line 16 having an external diameter of 2 /8", housing 26 was fabricated of a 2 /8" seamless tube of ordinary carbon steel and actuator rod 48 was formed of a stainless steel rod 1 1" in diameter and 36" long. In this arrangement the temperature at which the valve operates is regulated by adjustment of the position of threaded disc 50 in the lower end of the housing or tube.

Certain modifications of the invention will become apparent to those skilled in the art and the illustrative details disclosed are not to be construed as imposing unnecessary limitations on the invention.

I claim:

1. A heat-operated valve assembly comprising, in combination:

an elongated hollow valve body having an axial inlet port in one end, a transverse valve seat in said inlet port, at least one outlet port thru its wall downstream of said seat, and means at said inlet port for attaching said valve body to a cooling fluid supply tube;

a valve head disposed across said valve seat in said valve body, normally seated on said seat, and movable ofr said seat toward said inlet end to permit fluid flow thru said valve body to said outlet port;

a housing attached to the other end of said valve body coaxially therewith;

sealing means disposed in said valve body downstream from said outlet port to prevent fluid flow into said housing from the interior of said valve body; and

r 4 an elongated axially disposed heat expansible actuator rod, of substantially higher coelficient of expansion than said housing, fixed within said housing to a section thereof remote from said valve head, and expansible at elevated temperatures to cause movement of said valve head offsaid valve seat.

2. The valve assembly of claim 1 wherein said sealing means is disposed betweena section of said actuator rod and the surrounding wall.

3. The valve assembly of claim 1 wherein said valve head is mounted on a stem extending downstream into said housing and telescopes with the adjacent end of said actuator rod; and a spiral spring is disposed around said valve stemdownstrearn from said valve head for biasing said valve head to said normally closed position on said seat. 7

4. The valve assembly of claim 3 wherein the end of said actuator rod which is remote from said valve body is fixed to a. plug threaded into the inner wall of said housing'to' provide longitudinal adjustment of said rod to control the actuating temperature level of said valve assembly. M

5. The valve of claim 3 attached at said inlet port to the bottom end of a coolant pipe extending from a fluid coolant supply above ground to an oil stratum thru a well penetrating said stratum for production of oil therefrom by in situ combustion wherein hot gases flow into said well.

6. The valve assembly of claim 1 wherein said valve head is a ball check valve held on its seat by fluid pres- Zuge and said actuator rod expands into contact with said 7. The valve of claim 6 attached at said inlet port to the bottom end of a coolant pipe extending from a fluid coolant supply above ground to an oil stratum thru a well penetrating said stratum for production of oil therefrom by in situ combustion wherein hot gases flow into said well.

8. The valve of claim 1 attached at said inlet port to the bottom end of a coolant pipe extending from a fluid coolant supply above ground to an oil stratum thru a well penetrating said stratum for production of oil therefrom by in situ combustion wherein hot gases flow into said well.

References Cited UNITED STATES PATENTS 306,352 10/1884 Prentiss 13779 X 386,098 7/1888 Whitner 13759 2,060,994 11/1936 Kindervater 137-79 X 2,213,950 9/ 1940. Crites. 2,436,727 2/1948 Murphy 13779 X 2,956,575 10/1960 Ammann 137-79 3,120,267 2/1964 Bayless 166224 X 3,240,270 3/1966 Marx 166ll X 3,343,598 9/1967 Meldav et al l66-11 3,343,598 9/1967 Meldau et al 1661l FOREIGN PATENTS 670,728 4/1952 Great Britain.

ERNEST R. PURSER, Primary Examiner IAN A. CALVERT, Assistant Examiner US. Cl. X.R. l3779; 166 224 

